This invention relates to a toner for developing an electrostatic image comprising a negative electrostatic charge control agent including azo-type iron complex salt, which is used for a toner or a powder paint.
An image formation process of an electrophotography system is applied to a copy machine, a printer or a facsimile. The electrophotography system is performed by developing an electrostatic latent image on a photosensitive frame with a photosensitive layer having inorganic or organic photoconductive materials by toner having frictional electrification, transferring the imaged toner and then fixing onto a paper.
A charge control agent which adjusts the electrification of the toner appropriately is beforehand added to the toner so as to quicken a rise speed of the electrification, electrify sufficiently, control a proper quantity of the electrification stably, improve electrification property, control an electrostatic latent image stably, rise up a speed for developing an electrostatic latent image, and form the vivid images with high quality.
For instance, as such charge control agent, negative electrified metallic complex salts are mentioned in Japanese Patent Provisional Publication Nos. 61-101558, 61-155463 and 62-177561.
In recent years, a copy machine and a printer cause high efficiency with improving resolution and so on. The electrophotography system is used with not only a high speed development but also a low speed development for widespread purposes. Therefore, it is required that the charge control agent causes faster rise speed of the electrification of the toner and more excellent electrification property. It also requires the agent to be able to form the vivid images with high resolution and be manufactured simply with the sufficient yield. The toner using the charge control agent is also required. Furthermore, it is required that the charge control agent is able to be used in a powder paint for an electrostatic powder printing method which attracts and bakes the electrostatic powder paint onto a surface of a frame work having charge.